Polysilanes: all-rounder base materials in PV. City Solar Technologie GmbH & Co. KG Bitterfeld-Wolfen, Nov 15, 2007

Transcription

1 Polysilanes: all-rounder base materials in PV City Solar Technologie GmbH & Co. KG Bitterfeld-Wolfen, Nov 15, 2007

2 Outline Introduction silanes as common base materials in PV polysilanes: potential all-rounders in Si-based thin film technologies conclusions Page 2

3 CITY SOLAR: LEADING PV POWER PROVIDER WITH STRONG TECHNICAL IN-HOUSE CAPABILITIES Founded in 2003 Up-to-date: ~40 MWp projects completed Revenue 2007 ~ 170 millions Core business Development, design, construction and operation of large scale PV power plants Differentiators: Technology focus / R&D Strong project development PV power plant in Göttelborn/Germany (4 MWp) Page 3

4 SOME REFERENCES PV power plant Sembach (Germany): 4 MWp. PV power plant Göttelborn (Germany): 4 MWp. PV power plant Saarbrücken (Germany): 4 MWp. Rooftop power plant Biberach (Germany): 1,5 MWp. Page 4

5 BENEIXAMA (SPAIN) 20MWp March 2007 Page 5

6 BENEIXAMA (SPAIN) 20MWp today s LARGEST PV SOLAR POWER PLANT WORLWIDE March 2007 Page 6

7 TECHNICAL COMPETENCE PROVIDES PERFORMANCE ADVANTAGE In-house experts select the best available products (inverters, transformers, etc.). City Solar module type ( PQ 200 ) has already been successfully installed in several PV power plants (e.g. Sembach, Saarbrücken, Biberach, Lindau, Beneixama / Spain) With its in-house competency City Solar is able to guarantee life-cycle costs Budget Actual 2006 in % kwh/kwp kwh/kwp SB FH % SB FH % SB FH % Sembach % Sembach % Sembach % KH Herrenwald % KH Kurz % City-Solar-modules PQ 200 in Beneixama (Spain / 20 MWp) Page 7

8 City Solar AG COMPANY SET-UP production partner project development engineering construction Operation&Maintance Investment in power plants Page 8

9 CITY SOLAR OUTGROWS THE MARKET CAGR : 326% (FC) Target BU Power Plants Gain market share in a +20% p.a. growth market Ł target > 50% p.a. growth until 2010 Ł City Solar in 2010 > 800m revenue (w/o possible mega projects) Turnover in Mio. Employees Page 9

10 Overview: our technology portfolio 1. Power plant engineering 5. Concentrator technology 2. Silicon and TF precursor production 6. Tracker / mover 3. Pure water 7. Mobile heat storage 4. ORC turbine 8. White Fuel / hydrogen on on demand Page 10

11 Silanes: base materials in PV common Silanes in PV: Siemens chunk sg-si, eg-si HSiCl 3 TCS FBR granular sg-si mg-si SiH 4 Silane FBR Siemens granular sg-si, eg-si chunk sg-si, eg-si a-si/µc-si PV modules PECVD TFT, FPD also in use for TF-PV: HSiCl 3, SiCl 2 H 2, SiH 4 (CVD precursors) Page 11

12 Silanes as common precursors for Si deposition: CVD thin film growth rate of typical gas phase precursors The thermal decomposition properties strongly depend on the number of substituted Cl atoms. Example: At ~850 C, SiH 4 has a 50 times higher growth rate than SiCl 4.

13 reported for Si 2 Cl 6 at 850 C What happens, if the silane contains more than on Si-atomin a Si-Si-bond? The Si-Si- bond breaks more easily than a Si-Cl-bond a huge influence on the thermal decomposition properties should be expected. This is exactlywhat is experimentallyobserved! Example: Si 2 Cl 6, the big brother of SiCl 4 reported for Si 2 Cl 6 at 450 C

14 Polysilanes in TF technology less common Poly -silanes already in use in TF technology: Si 2 Cl 6 Hexachlorodisilane today: $/kg CVD Si, Si-C, Si-O, Si-N higher rate/lower T! Si 3 Cl 8 Octachlorotrisilane?? $/kg Si 2 H 6 Disilane today: ~4000$/kg! CVD Si, Si-C, strained Si/Ge higher rate/lower T! Si 3 H 8 Trisilane today ~25000$/kg! PECVD a-si, µc-si higher deposition rate! a possible key towards cost reduction in a-si/µc- Si tandem thin film PV, but too expensive Si 5 H 10 cyclo-pentasilane??? k$/kg Printing, coating a-si, µc-si TFT potentially disrupting new Si-coating technology Page 14

15 PRINTABLE ELECTRONICS Liquid polysilanes as molecular precursors: enabling technology for Printable electronics and Electronic precursors liquid molecular precursor deposition/thermal processing Example (Seiko Epson 2006)

16 SI BASED PRINTED DEVICES CAN BE MADE It has been shown already that silicon based devices can be produced from H-Silanes with ink jet or spin coating processes. This could revolutionize the production technology of many electronic devices, if it would be possible to produce the required amount of these silanes at competitive cost. source: Seiko Epson 2006: Nature, April 2006 Precursor: Cyclopentasilan Si 5 H 10, dissolved in Toluol Auftrag: ink jet and spin coating Page 16

17 SIGNIFICANT COST SAVINGS BECOME POSSIBLE CS-Technology is capable of producing the required silanes at competitive costs source: Seiko Epson 2006 Page 17

18 City Solar approach to Polysilanes FROM THE IDEA OF PRODUCING SOLAR SILICON TO AN ARRAY OF MULTI-GENERATION APPLICATIONS Laboratory micro wave, Frankfurt university, spring 2005 SiO 2 Polysilane, PCS Pyrolysis Solar Silicon SiCl 4 Plasma technology Si n Cl 2n, Si n Cl 2n+2 Derivatization coatings (SiC, Si 3 N 4,SiOx) silicide layers doped Si + Si/Ge layers Hydration PV thin film printable electronics alternative fuels New chemical compounds in industrial quantities The potential of our technology goes far beyond SG-Silicon: It turned out to be the key to numerous applications in the electronics, materials, and energy market with outstanding growth potentials Page 18

19 From a new solar Si production process to a world of applications Common wafer-based PV TF-PV + electronics electronics beyond oil further processing Silane product mono Multi casting Ribbon Thick film wafer subst. a-si TF µc-si TF c-si TF Si-C Si-N H2 storage /fuel Chloro-Polysilane (PCS) Cl-Oligosilanes Raw PCS Raw PCS H-Oligosilanes n 8 H-Oligosilanes n 8 feasibility TF precursors gas phase and liquid phase Granular poly-si Solid H- Polysilane (HPS) TF precursors gas phase TF precursors liquid phase

20 The solar Si project Page 20

21 City Solar process for SG-Si production SG-Silicon production through pyrolysis (thermal decomposition) of chlorinated polysilanes. 1.Plasma polymerisation (T = Room Temperature) Polysilane, PCS SiCl 4 + H 2 + energy fi Si n Cl 2n + Si n Cl 2n+2 + HCl Si n Cl 2n + Si n Cl 2n+2 + Δ fi Si + SiCl 4 2. Thermal decomposition (T >400 C) Page 21

22 FAST-TRACK DEVELOPMENT OF THE PLASMA-CHEMISTRY TECHNOLOGY yearly throughput of a single plasma system (in t 365/24/7 10,0 1,0 ~1,0t/a target ~10t/a 0,1 ~50kg/a 0,01 0,001 1kg/a 0,0001 0, ,01kg/a Q2/2005 Q4/2005 Q1/2006 Q4/2006 Q4/2007 Page 22

23 Si project: the granular Si product -Our granular Si can be melted with standard production technologies -cells with City Solar Si admixture are as good as cells made from 100% standard Si -poly Si wafers from100% City Solar Si are p-type with following room temperature electrical properties: -resistivity of 4 4,5 Ohmxcm, -free carrier concentration p=5*10 15 cm -3, -mobility µ ~ 300 cm 2 /(Vs) -CZ single crystals grown (IKZ Berlin) from 100% City Solar granular Si. The material is p-type, 10 Ohmxcm. Further properties are under investigation (ISE Freiburg). October 2006: first successful production tests with the solar silicon of City Solar Page 23

24 Polysilane portfolio from plasma PCS technology Readily available via Plasma-Polysilane technology: Si 2 Cl 6 Si 3 Cl 8 Hexachlorodisilane Octachlorotrisilane Today commercial precursor product NEW precursor product Si 4 Cl 10, Si 5 Cl 12, solid Cl-Polysilanes NEW precursor products NEW precursor products PCS Si 2 H 6 Si 3 H 8 Disilane Trisilane Today commercial product Today commercial product Si n Cl (2n+2) + Si n Cl 2n Si 4 H 10, Si 5 H 12, solid H-Polysilanes n>20 NEW precursor products NEW precursor products Many other isomers and derivates NEW precursor products Page 24

25 From a new solar Si production process to a world of applications Common wafer-based PV TF-PV + electronics electronics beyond oil further processing Silane product mono Multi casting Ribbon Thick film wafer subst. a-si TF µc-si TF c-si TF Si-C Si-N H2 storage /fuel Chloro-Polysilane (PCS) Cl-Oligosilanes Raw PCS Raw PCS H-Oligosilanes n 8 H-Oligosilanes n 8 feasibility TF precursors gas phase and liquid phase Granular poly-si Solid H- Polysilane (HPS) TF precursors gas phase TF precursors liquid phase

26 PRODUCT PIPELINE SI PLASMA - POLYMERS SiCl 4 CPS [Si n Cl 2n+2 ]; n>1 HPS [Si n H 2n+2 ]; n>1 bulk silicon Si 2 Cl 6 Oligosilane [Si n H 2n+2 ]; n = 2-8 liquid silane precursor [Si n X 2n+2 ]; n =2-8 solid H-Silane [Si n H 2n+2 ]; n > 8 time-to-market ~1year ~1 year 1 2 years ~3 years > 3 years market PV electronics electr. & PV electr. & PV energy storage Page 26

27 Conclusion Chlorinated Plasma-Polysilanes have been developed as a easy-todecompose interstage product for bulk Si production and turned out to be allrounders for low-cost thin film deposition. A novel industrial polysilane production process was developed and successfully up-scaled. The existing engineering of a bulk-si Fab yields the up-scaling option for a multi-1000t/y, low cost production of high-performance precursors. An impressive portfolio of liquid/gaseous precursors for many all functional layers in electronics and PV becomes accessible. Unless a polysilane-based bulk Si production, the start-up of a precursor production with a capacity of <100t/y PCS is possible based on today s mature pilot technology and with an affordable capital. It gives, however, a huge leverage towards >>100MWp/y of solar modules at highly competitive costs already. Page 27